Field of the Invention
The present invention relates to an organic light emitting element.
Description of the Related Art
An organic light emitting element is an element including an anode, a cathode, and an organic compound layer arranged between the electrodes. Holes and electrons injected from the electrodes recombine in an emission layer which is the organic compound layer to produce excitons, and the organic light emitting element emits light upon return of the excitons to the ground state. Recent development of the organic light emitting element is significant, and allows the organic light emitting element to be a light emitting device having the following features: a low drive voltage; light emission at various wavelengths; high-speed responsiveness; a small thickness; and a light weight.
In the organic light emitting element, it is important to improve an electron injection property from the viewpoint of reducing a voltage of the element. An approach to improving the electron injection property is, for example, an approach involving using an alkali metal as a constituent material for the organic light emitting element, in particular, an electron injection material. However, the alkali metal involves a problem in that the metal has high water solubility and hence the moisture resistance of the organic light emitting element reduces. Lodz. Towarz. Nauk: Wydzial III, Acta Chim. (1958), 3, P93-97. discloses a method of synthesizing the following compound a-1 and chemiluminescence involving using the compound. In addition, Guangpuxue Yu Guangpu Fenxi Volume 18 Issue 6 Pages 669-672 1998 discloses charge transfer in a solution using the following compound a-2.
